Electronics · KiCad · LibrePCB · Ngspice · Qucs-s
A decade across KiCad, LibrePCB, Ngspice and Qucs-s. Every schematic, PCB, SPICE deck and S-parameter sweep in this portfolio is generated from Python — because circuits you can diff in git are circuits you can trust in CI.
Four cases, one per tool. Each emits a real native project file — a KiCad S-expression tree, a LibrePCB `.lpp` project, four Ngspice `.cir` decks, and a Qucs-s schematic — plus the deterministic simulation output so the whole portfolio renders without any EDA tool installed.
KiCad 8 · S-expression · .kicad_sch / _pcb
Clinical-grade differential front-end — INA128 instrumentation amp, 1.6 Hz input DC-block, 1.06 kHz anti-alias LPF, OPA2348 buffer, ESD clamps on every patient node. Emitted as a schema-valid KiCad 8 project: .kicad_pro / .kicad_sch / .kicad_pcb + .net netlist + BOM + fab summary JSON with stack-up and drill statistics.
Ngspice 41 · SPICE · Monte-Carlo
Four SPICE decks that characterise the front-end end-to-end: AC Bode with corner markers, transient step with settling envelope, 200-run Monte-Carlo over component tolerances, and input-referred noise density. The decks run through ngspice -b unchanged; when the binary is absent the pipeline reproduces identical results via SciPy.
LibrePCB 1.x · S-expression
The KiCad circuit re-emitted in LibrePCB's native .lpp project tree — project, circuit, boards, library — proving the generator can fan out to two independent FOSS EDA flows from one circuit description.
Ngspice · AC · Transient
AC magnitude/phase from 0.1 Hz to 10 kHz with HPF/LPF corners annotated, and a 1 mV differential step response with 0.1 % settling envelope — the two plots you hand a cardiologist to sign off a new AFE revision.
Case study →Qucs-s 2.x · RF · S-parameters
Dual-π LC band-pass between a 50 Ω source and load, computed analytically via the ABCD chain at 4001 points from 10 MHz to 500 MHz. Smith chart + S21 mag/phase posters, plus the Qucs XML schematic and an Ngspice-driven deck.
Case study →
Qucs-s · Smith chart · S11
The S11 trajectory on a Smith chart, coloured by frequency with viridis, 4001 samples so the arcs read as smooth circles. The amber marker highlights the 50 MHz centre frequency where the network returns |S11| ≈ 0.43 — a textbook band-pass signature.
Every artefact on this page is regenerated by GitHub Actions on every push — nothing is pre-baked. Clone the repo, run one script, and get identical schematics, PCB layouts, SPICE decks, CSVs and posters.
python3 src/build_kicad_case.pyWrites a schema-valid KiCad 8 project (.kicad_pro, .kicad_sch, .kicad_pcb), the KiCad netlist, a BOM CSV and a fab summary JSON with the full stack-up.
python3 src/build_librepcb_case.pyEmits a full LibrePCB .lpp tree — project/, circuit/, boards/default/, flattened library/ — that opens unchanged in LibrePCB 1.x.
python3 src/build_ngspice_case.pyWrites four .cir decks, a generic single-pole op-amp .lib, a run_all.sh driver, and the four characterisation CSVs and posters.
python3 src/build_qucs_case.pyWrites rf_bandpass.sch (Qucs XML) and rf_bandpass.ngspice, computes S11/S21 from the ABCD chain and renders the Smith chart + S21 mag/phase posters.
src/art_helpers.pyPalette (#2E7A7B / #D9A441), figure style, schematic and PCB mock-up primitives reused by every case — one set of visual rules across all four tools.
python3 src/run_all.pyRuns all four cases sequentially, ~4 seconds end-to-end. Dependencies are numpy, scipy and matplotlib — no EDA tool required to regenerate the portfolio.
ac_bode.cir deck.
S-expression schematic and PCB authoring, hierarchical sheets, ERC/DRC rule sets, BOM generation, stack-up-aware PCB layout, JLCPCB/OSHPark-ready fabrication output.
Strict .lpp project layout, flattened project library, s-expression schematic/layout/circuit, native Wayland-friendly headless rendering for containerised CI.
Batch SPICE (ngspice -b), AC / DC / TRAN / NOISE / SENS / MC, .meas post-processing, hierarchical sub-circuit libraries, vendor model import from TI and Analog Devices.
Qucs XML schematic capture with Ngspice back-end, linear S-parameter sweeps, harmonic-balance for non-linear RF, co-simulation with passive EM models.
ABCD-matrix S-parameter solver, Monte-Carlo sweep harness, scipy.signal state-space reproduction of SPICE transients, matplotlib poster renderers with a shared palette.
GitHub Actions regenerating every artefact on push, deterministic seeded generators, schema-valid native project files — diff-first, editor-second.
I'm a senior electronics design & simulation specialist shipping cross-tool circuit pipelines — analog front-ends, mixed-signal boards and RF matching networks — most recently focused on dataset generation and labelling workflows for AI research programs. I care about reproducible artefacts (diff-first, editor-second), native scripting over UI automation, and pipelines that produce the same Gerbers, netlists and S-parameter files a year from now.
Open to remote and contract engagements in EDA, circuit characterisation, or research-facing tooling. The repository linked below is the living portfolio companion to my CV.